Here is the full list of all 50 Tomb Raider achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Fully mod and completely upgrade all weapons.
Kill 2 multiplayer enemies with a single explosive.
In multiplayer, be the only player on your team that isn't dead or downed.
Catch a player in a snare trap in multiplayer.
Find all documents, relics and GPS caches.
Complete all optional tombs.
Kill and loot 10 flying animals (crows and gulls).
Purchase all skills in all categories.
Complete the game.
Shoot a bundle of dynamite out of the air.
Fully mod and completely upgrade any weapon.
Find 75% of GPS caches.
Collect 75% of all relics.
Find 75% of all documents.
Kill FeeFee the crab.
Kill 75 enemies with the rifle.
Loot 200 enemies.
Kill and loot 10 small animals (rabbits, chickens, rats).
Purchase all skills in one category.
Kill 25 unaware enemies.
Perform 15 finishers.
Force an enemy to drop dynamite that kills two people when exploding.
Find 25% of GPS caches.
Collect 5000 pieces of salvage.
Collect 25% of all relics.
Kill 35 enemies with the pistol.
Kill 50 enemies with the bow.
Perform 50 headshot kills in the single player campaign.
Find 25% of all documents.
Complete one challenge.
Complete one optional tomb.
Kill and loot 10 large animals (deer, boar, wolves).
Kill 40 enemies with the shotgun.
Rope pull 5 enemies off edges.
Shoot 10 enemies off zip lines.
Incapacitate 25 enemies with dodge counter.
Complete all challenges.
Complete all conversations with the Endurance crew.
Complete a match in all multiplayer modes.
Kill 20 enemy players in multiplayer using a turret.
Kill a zip-lining enemy player in multiplayer.
Survive 10 explosions in multiplayer.
Revive a teammate in a multiplayer match.
Win a ranked match in every multiplayer mode.
Kill 10 multiplayer enemies using your melee attack.
In multiplayer, escape death 3 times by using the rope ascender.
Purchase a new multiplayer character.
Reach level 10 in multiplayer.
Buy every upgrade and character in multiplayer.
Reach level 60 in multiplayer.